The forecasting study also found that 42 percent of the U.S. population could be obese by 2030.

The findings suggest the U.S. health care system could be burdened with 32 million more obese people within two decades. Action is needed to keep rates from increasing further, according to the research from Duke University, RTI International, and the Centers for Disease Control and Prevention (CDC).

The study, based on data from the Behavioral Risk Factor Surveillance System and state-level data from the Bureau of Labor Statistics and other organizations, was published in the American Journal of Preventive Medicine on May 7.

The study also forecasts an increase in the number of individuals with severe obesity, with rates rising to 11 percent by 2030. Severe obesity is defined as a body mass index over 40 or roughly 100 pounds overweight.

Severely obese individuals are at highest risk for the health conditions caused by excess weight, resulting in substantially greater medical expenditures and rates of absenteeism.

"Should these forecasts prove accurate, the adverse health and cost consequences of obesity are likely to continue to escalate without a significant intervention," notes senior author Justin Trogdon, PhD, of RTI.

"We know more than ever about the most successful strategies that will help Americans live healthier, more active lives and reduce obesity rates and medical costs," said William H. Dietz, MD, PhD, director of CDC's Division of Nutrition, Physical Activity and Obesity.

"People need to make healthy choices, but the healthy choices must first be available and accessible in order to make them," Dietz said. "In the coming days at our Weight of the Nation conference, CDC and its partners will emphasize the proven, effective strategies and solutions that must continue to be applied to help make the healthy choice the easy choice."

On May 8, a set of potential solutions will be released at the CDC conference. The Institute of Medicine will issue a new report, "Accelerating Progress in Obesity Prevention: Solving the Weight of the Nation," which provides the results of a comprehensive review of obesity prevention-related recommendations. The report will identify strategies and action steps that have the greatest potential to speed up progress in combating the obesity crisis.

To view the study, "Obesity and Severe Obesity Forecasts through 2030," visit www.ajpmonline.org on May 7 after noon Eastern Time, or for a copy, contact AJPM Editorial Office at 858-534-9340 or eajpm@ucsd.edu.